title: HINTEGRA revision arthroplasty for failed total ankle prostheses.
abstract: BACKGROUND
  When a total ankle replacement fails, arthrodesis has been advocated as the treatment of choice. With the availability of a wide spectrum of implants, revision arthroplasty may become a viable alternative.
  
  
  METHODS
  We reviewed a consecutive series of 117 cases (116 patients [fifty-six female and sixty male]; mean age, 55.0 ± 12.0 years) in which a total ankle arthroplasty failed after a mean of 4.3 years and was revised with use of the HINTEGRA three-component total ankle prosthesis. The reason for revision involved the metallic components in sixty ankles (51%), the bone in twenty-eight (24%), the soft tissues in twenty (17%), and infection in nine (8%). The talar component was revised in 104 ankles (89%) and the tibial component, in 106 (91%).
  
  
  RESULTS
  Early complications included a fracture of the malleoli in two ankles and a dislocation of the polyethylene insert in one. Seventeen (15%) of the revision arthroplasties required further revision surgery, in most cases for loosening of one or two of the prosthetic components. The mean American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score for the remaining 100 ankles (85%) improved from 44 ± 18 preoperatively to 72 ± 19 (p < 0.01) at the time of the latest follow-up (mean, 6.2 years). The estimated survival of the revision arthroplasties at nine years, with loosening of components as the end point, was 83%. The prevalence of component loosening was higher (p < 0.005) with the use of single-coated hydroxyapatite components (six of twenty-three ankles, 26%) than with double-coated components (five of ninety-four ankles, 5%). The correlation between the extent of bone loss at the resection surface and the prevalence of component failure was weak and not significant.
  
  
  CONCLUSIONS
  The medium-term results of revision arthroplasty after a failed total ankle arthroplasty were similar to those after primary arthroplasty. The key to success was firm anchorage of the components to primary bone stock. A single hydroxyapatite component coating should no longer be used for revision total ankle arthroplasty.
authors.affiliation: Clinic of Orthopaedic Surgery, Kantonsspital Baselland Liestal, Rheinstrasse 26, CH-4410 Liestal, Switzerland. beat.hintermann@ksli.ch
authors.forename: Beat
authors.initials: B
authors.lastname: Hintermann
authors.forename: Lukas
authors.initials: L
authors.lastname: Zwicky
authors.forename: Markus
authors.initials: M
authors.lastname: Knupp
authors.forename: Heath B
authors.initials: HB
authors.lastname: Henninger
authors.forename: Alexej
authors.initials: A
authors.lastname: Barg
mesh_terms: D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000601:surgery*; D001174:Arthrodesis; D019643:Arthroplasty, Replacement; D005260:Female; D006801:Humans; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000601:surgery*; D011182:Postoperative Care; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome